Transfer assembly for a press



March 4, 1969 J, MQELRQY TRANSFER ASSEMBLY FOR A PRESS Sheet Filed Oct.16, 1 96? 9 i a 4f y 5 a 3 My 4 3 1 g w z 4 0 J 1 kflfi W. 0 J 5 4 J a l& 33

March 4, 1969 H. J. MOELROY 3,430,779

TRANSFER ASSEMBLY FOR A PRESS Filed Oct. 16, 1967 Sheet 3 of 2 UnitedStates Patent 3,430,779 TRANSFER ASSEMBLY FOR A PRESS Howard J. McElroy,South Holland, 111., assignor to Verson Allsteel Press Company, Chicago,111., a corporation of Delaware Filed Oct. 16, 1967, Ser. No. 675,581US. (Tl. 214-1 Int. Cl. 1325 3/00; 1866c 1/10; B65g 9 Claims ABSTRACT OFTHE DISCLOSURE The principal object of this invention is to provide animproved gripper finger mechanism for a transfer assembly of a press.Briefly, the gripper finger mechanism of this invention includes abracket which may be secured to a feed bar and which is provided with apair of parallel guide tracks extending at right angles to the feed bar.A lever is pivotally mounted on the bracket and is movable between aposition substantially normal to the guide tracks and a positionsubstantially in alignment with the guide tracks. A first finger memberhaving gripping means on its outer end is pivotally connected at itsinner end to the pivoted lever, and rollers carried by the first fingermember intermediate its ends are arranged in the guide tracks. A secondfinger member having gripping means at its outer end carries rollers atits inner end which are arranged in the guide tracks inwardly from therollers on the first finger member. The first and second finger membersare pivotally connected together at a point between the rollers thereof.

In operation, the first and second finger members are retracted and thegripping means thereof are separated when the pivoted lever is in thesubstantially normal position, and the first and second finger membersare advanced and the gripping means thereof are closed when the lever isin the substantially aligned position for gripping a work piece. Thelever is rotated between the aforementioned positions by an oscillatingrod so that the advancing and retracting of the finger members and the aclosing and opening of the gripping means thereof are afforded bymovement of a single oscillating rod.

Further objects of this invention reside in the details of constructionof the gripper finger mechanism and the cooperative relationshipsbetween the component parts thereof.

Other objects and advantages of this invention will become apparent tothose skilled in the art upon reference to the accompanyingspecification, claims and drawings in which:

FIG. 1 is a top plan view of the gripper finger mechanism of thisinvention with the gripper finger members thereof advanced and closed;

FIG. 2 is a vertical sectional view through the gripper finger mechanismtaken substantially along the line 2-2 of FIG. 1 but illustrating thegripper finger members retracted and opened;

FIG. 3 is a view similar to FIG. 2 but illustrating the gripper fingermembers being moved toward their advanced and closed positions;

FIG. 4 is a view similar to FIG. 2 but illustrating the gripper fingermembers advanced and closed;

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FIG. 5 is a vertical sectional view taken substantially along the line55 of FIG. 4;

FIG. 6 is a vertical sectional view taken substantially along the line66 of FIG. 4;

FIG. 7 is a vertical sectional view taken substantially along the line77 of FIG. 4; and

FIG. 8 is a vertical sectional view taken substantially along the line8--8 of FIG. 4.

The gripper finger mechanism of this invention is generally designatedat 10 in the drawings. It includes a bracket 11 having a bottom wallprovided with mounting flanges 12 for receiving screws 13 for mountingthe bracket on a feed bar 14, the feed bar 14 extending along the press(not shown) and the bracket .11 being mounted at right angles to thefeed bar 14. The bracket has a pair of spaced apart upstanding sidewalls 15 which are internally provided with longitudinally extendingguide tracks 16. The side walls 15 are also provided with openings 17which are in substantial alignment with the guide tracks 16, theseopenings 17 receiving ball bearings 18 which are held in place in theopenings by screws 19. The ball bearings rotatably mount a splined shaft20 in substantial alignment with the guide tracks 16. The ball bearings18 in addition to permitting rotation of the shaft 20 also allow forrelative longitudinal movement therebetween. Therefore, the gripperfinger mechanism It can be slidably located along the spline shaft 20 inorder to position gripper finger mechanism to optimum working area forvarious parts and spaced to suit desired transfer distance.

An actuator member 22 having a pair of spaced apart legs 23 is splinedon the splined shaft 20 so that the bracket 22 is rotated as the shaft20 is rotated. A lever 24 is rotatably mounted on the shaft 20 betweenthe legs 23 of the actuator member 22 and the lever 24 is provided witha pair of shoulders 25 which are engaged by adjustable screws 26 carriedby the actuator member 22. The screws 26 engaging the shoulders 25operate to rotate the lever 24 as the actuator member 22 is rotated bythe shaft 20. By adjusting the screws 26 the relative positions of theactuator member 22 and the lever 24 may be predetermined.

A first finger member 28 is pivoted at its inner end to the lever 24 bya pivot pin 29, the lever 24 being received within a notch 30 in theinner end of the first finger member 28. The finger member 28 is alsoprovided with an opening 31 and outwardly beyond this opening of thefinger member 28 carries a pin 32 which in turn carries a pair ofrollers 33 arranged within the pair of guide tracks 16. The outer end 36of the finger member 28 carries a gripping means or pad 34 which is heldin place by screws 35. The pad 34 is for the purpose of gripping a workpiece to be transferred along the press.

A second finger member 38 extends through the opening 31 in the firstfinger member 28 and it is provided at its inner end with an enlargedcylindrical portion 39 which carries a pin 41 for mounting rollers whichalso are arranged in the guide tracks 16. The outer end 42 of the secondfinger member 38 is provided with a pair of openings for receivingscrews 44 which in turn carry a mounting means or pad 43. The mountingpad 43 and screw 44 are urged downwardly by means of springs 46 and theamount of downward movement is limited by nuts 45 carried by the screws44. The screws 44, nuts 45 and springs 46 form a spring biased lostmotion connection between the outer end 42 of the second finger member38 and the gripping means or pad 43. The pad 43 is also for the purposeof gripping a work piece to be transferred along the press. The secondfinger member 38 where it extends through the opening 31 in the firstfinger member 28 is provided with a pivot pin 48 held in place thereinby a set screw 49. The pivot pin 48 extends through the first fingermember 28 for the purpose of pivotally connecting together the firstfinger member 28 and the second finger member 38. This pivotalconnection be tween these finger members is arranged between the rollers33 and 40 carried by these finger members. The work piece to be grippedand transferred by the gripper finger mechanism may be in the form of ablank or the like and is designated at 50 in FIGS. 2. to 4.

Referring now to FIGS. 2 to 4, the gripper finger mechanism is shown inFIG. 2 to be in its retracted positionwith the gripping pads 34 and 43separated. In this position the lever 24 is substantially normal to,i.e., substantailly at right angles to, the guide tracks 16. In thisposition the first finger member 28 and, hence, the second finger member38 are retracted and the rollers 33 and 40 are toward the inner end ofthe guide tracks 16. Since the lever 24 is substantially normal to theguide tracks 16 the inner end of the first finger member 28 is in araised position and, hence, the outer ends 36 and 42 of the fingermembers 28 and 38 are separated.

As the lever 24 is moved from the position illustrated in FIG. 2 to theposition illustrated in FIG. 3, the principal motion applied to thelever 28 is an outward or advancing motion which causes the rollers 33and, hence, the rollers 40 to move outwardly along the guide tracks 16.In this way, the finger members 28 and 38 are advanced over the workpiece 50 but yet the gripping means or pads 34 and 43 remain separated.

As the lever 24 is moved from the position illustrated in FIG. 3 to theposition illustrated in FIG. 4 wherein the lever 24 is in substantialalignment with the guide tracks 16, the principal movement applied tothe inner end of the first finger member 28 is a downward movement. Thisdownward movement causes the outer end 36 of the first finger member 28to move upwardly and the outer end 42 of the second finger member 38 tomove downwardly. By reason of this motion the gripping means or pads 34and 43 operate to grip the work piece 50 therebetween, there beingsubstantially no further advancing of the finger members 28 and 38 asthe pads 34 and 43 grip the work piece 50. When the pads 34 and 43 gripthe work piece as illustrated in FIG. 4, the spring 46 operates toprovide a resilient gripping action, there being a slight additionalmovement of the outer end 42 of the second finger member 38 with respectto the screws 44.

After the work piece 50 is gripped in the manner described above, thefeed bar 14 is longitudinally moved to another station along the press.When the work piece has thus been transferred to the next station, thesplined shaft 20 is rotated in the opposite direction to separate thegripping means or pads 34 and 43 from the work piece as illustrated inFIG. 3 and to retract the finger members 28 and 38 as illustrated inFIG. 2. In this way, the work piece is released and then the feed bar 14is returned to its initial position for gripping another work piece tobe transferred thereby. The feed bar 14 may carry a plurality of gripperfinger mechanisms therealong so that the work pieces may beprogressively advanced along the press if this be desired. Also, it maybe desirable to grip opposite edges of the work piece 50 and to do thisa second feed bar is arranged on the opposite side of the work piece andis provided with a plurality of gripper finger mechanisms. In suchevent, both of the feed bars 14 would be simultaneously advanced andretracted and the finger members 28 and 38 of the opposed gripper fingermechanisms on opposite sides of the work piece would also besimultaneously operated.

While for purposes of illustration one form of this invention has beendisclosed, other forms thereof may become apparent to those skilled inthe art upon reference to this disclosure and, therefore, this inventionis to be limited only by the scope of the appended claims.

I claim:

1. In a transfer assembly for a press a gripper finger mechanism forgripping and releasing a work piece comprising, a bracket having a pairof parallel guide tracks, a lever pivotally mounted in said bracket andmovable between a position substantially normal to said guide tracks anda position substantially in alignment with said guide tracks, a firstfinger member having gripping means on its outer end and being pivotallyconnected at its inner end to said pivoted lever, rollers carried bysaid first finger member intermediate its ends and arranged in saidguide tracks, a second finger member having gripping means at its outerend, rollers carried by said second finger member at the inner endthereof and arranged in said guide tracks inwardly from the rollers ofsaid first finger member, and a pivotal connection between said firstand second finger members at a point between the rollers thereof,whereby said first and second finger members are retracted and thegripping means thereof are separated when said lever is in saidsubstantially normal position and whereby said first and second fingermembers are advanced and the gripping means thereof are closed when saidlever is in said substantially aligned position for gripping a workpiece.

2. The combination of claim 1 wherein said gripping means on the outerend of one of said finger members includes a gripper jaw and a springbiased lost motion connection between the gripper jaw and the fingermember, whereby the work piece is resiliently gripped by the grippingmeans on the first and second finger members.

3. The combination of claim 1 wherein the lever is moved over centerwhen it is moved to said substantially aligned position.

4. The combination of claim 2 wherein the lever is moved over centerwhen it is moved to said substantially aligned position.

5. The combination of claim 1 including a shaft rotatably journaled bythe bracket and upon which the lever is pivotally mounted, an actuatormember secured to said shaft, and an adjustable connection between saidactuator member and said lever for rotating said lever as said shaft isrotated.

6. The combination of claim 5 wherein said shaft is splined and thesecuring of said actuator member to said shaft is by a splinedconnection whereby relative longitudinal movement of said actuatormember and said shaft is provided.

7. The combination of claim 5 wherein said adjustable connection betweensaid lever and said actuator member includes a pair of shoulders on saidlever and a pair of adjusting screws on said actuator member engagingthe shoulders on said lever.

8. The combination of claim 1 wherein the bracket of said gripper fingermechanism is mounted on a feed bar which is longitudinally movable forlongitudinally transferring work pieces gripped by the gripping meansthereof.

9. The combination of claim 6 wherein the bracket of said gripper fingermechanism is mounted on a feed bar which is longitudinally movable forlongitudinally transferring work pieces gripped by the gripping meansthereof, the splined connection between the actuator member and theshaft permitting such longitudinal movement.

FOREIGN PATENTS 560,634 4/1957 Italy.

GERALD M. FORLENZA, Primary Examiner.

G. F. ABRAHAM, Assistant Examiner.

US. Cl. X.R.

